1. Field of the Invention
This invention relates to vaccum cleaner structures and in particular to beater brush structures for use in vacuum cleaners.
2. Description of the Background Art
It is conventional to provide in vacuum cleaners a suction nozzle having mounted internally thereof driven means for agitating the surface being cleaned, such as a carpet or the like, for improved removal of dirt therefrom. In one form, the dirt-agitating means comprises an agitator in the form of a rotatable brush which is driven by means of a belt or the like, either from the suction fan motor or a separate brush motor.
It is also conventinal to provide in such dirt-agitating devices beater bars or the like comprising relatively rigid projections which are engaged with the surface to be cleaned on rotation of the brush.
In one form, the beater brush is driven rotatively by a cog belt drive having a sprocket associated with the brush assembly driven by a cog belt from a suitable drive motor. One example of such a vacuum cleaner structure is that of Wilbur-Webb Selley et al U.S. Pat. No. 3,608,333.
An example of a dirt-agitator assembly having both brushes and beater elements is that disclosed in U.S. Pat. No. 4,209,873 of Harold W. Schaefer. As shown therein, the roller carrying the brush and beater element is provided with an annular groove for receiving a drive belt to effect rotation thereof, the groove being disposed at an axially midportion of the roller.
It has further been conventional in prior art vacuum cleaner dirt agitators to provide the brush tufts in insert strips mounted to the roller for facilitated manufacture. One example of such a strip-mounted brush structure is that disclosed in U.S. Pat. No. 3,874,017 of Russell H. R. Parker.
A problem encountered in such vacuum cleaner dirt agitators is the entrainment of fibrous material, such as thread material, between movable parts of the system. Thus, as shown in U.S. Pat. No. 2,260,235 of Donald G. Smellie, it is known to provide thread guards in the form of end caps at the opposite ends of the beater brush assembly.